Complete the recursive formula of the geometric sequence $-0.1\,,-0.5\,,-2.5\,,-12.5,...$. $c(1)=$
The first term is $-0.1$ and the common ratio is $5$. ${\times 5\,\curvearrowright}$ ${\times 5\,\curvearrowright}$ ${\times 5\,\curvearrowright}$ $-0.1,$ $-0.5,$ $-2.5,$ $-12.5,...$ This is the recursive formula of $-0.1\,,-0.5\,,-2.5\,,-12.5,...$. $\begin{cases} c(1)=-0.1 \\\\ c(n)=c(n-1)\cdot 5 \end{cases}$